58 Rev. T. R. R. StehUng — On Calceola sandalina. 



making it a bivalve; Lamarck placed it in his order Eudistes, of 

 whicli Woodward writes that ''they are the most problematic of all 

 fossils ; " 1 Davidson figures it in the General Introduction to his 

 noble Monograph of the Fossil Brachiopoda of Great Britain, pub- 

 lished by the Palseontographical Society in 1853. It has since then 

 been transferred by the labours of Professors Suess and Lindstrom 

 to the Zoantharia rugosa, which are commonly regarded as Corals.^ 

 There has been, therefore, a curious game of " hunt the slipper," 

 not without some very interesting and instructive results. 



Lindstrom's paper on the subject, translated by himself from the 

 original Swedish, will be found in the Geological Magazine for 1866.^ 

 Already, in 1853,3 Davidson had remarked that of all the genera 

 among the Brachiopoda, Calceola seemed the most abnormal; that no 

 one had been able to point out the probable structure of the animal, 

 nor its true position in the Class ; that while so ponderous a shell 

 demanded a powerful muscular system, no traces of such a system 

 had been observed in the interior of the valves; and that in some 

 examples so much calcareous matter had been deposited as to leave 

 but little free space for lodging the animal. These acute observations 

 must have led him to the very verge of discovering the true state of 

 the case ; but, unfortunately, Dr. Carpenter, whose paper " On the 

 Intimate Structure of the Shells of Brachiopoda" is prefixed to 

 Davidson's Monograph, though he examined several specimens of 

 Calceola sandalina, did not meet with one in which the texture was 

 sufficiently well preserved to enable him to speak positively as 

 to its chara,cter. 



Later on, Milne-Edwards seems to have had the clue in his hand, 

 to have been " very warm," as children say in playing at " hide-and- 

 seek." In placing the Silurian genus Goniophyllum among the 

 Zoantharia rugosa, he tells us that it had been regarded as a 

 Brachiopod shell, and that in fact it has some external resemblance to 

 Calceola of Lamarck, but that the sections of it he had made left no 

 doubt of its true affinities. Had he made similar sections of Calceola 

 under favourable circumstances, he would have seen that its true 

 affinities were just the same as those of Goniophyllum, the affinities of 

 neither being with the Brachiopods, but of both with the Zoantharia 

 rugosa.* 



It may appear remarkable that so many keen observers should 

 have mis-placed in the Molluscan sub-kingdom forms properly 

 belonging to the sub-kingdom of the Coelenterata, but there are extenu- 

 ating circumstances. All the soft parts of the animals in question 

 perished long ago ; what was left looked much more like the shell 

 of a Mollusc than the stony deposit of the Zoantharia. For several un- 

 doubted Brachiopods — Spirifera exporrecta (Silurian), Cyrtina lietero- 

 clita (Devonian), Spirifera simplex (Devonian), and others — had much 



^ Manual of the Mollusca, by S. P. Woodward, 1851-56, part ii. p. 280; second 

 edition, p. 441. 



2 Vol. III. p. 356, PI. XIV. and p. 406. 



3 See " Fossil Brachiopoda of Great Britain," Davidson, in the Devonian series. 

 Palseontographical vol. 1863, pub. 1865. 



* Histoire des Coralliaires, vol. iii. p. 397. 



